Meridional Flows, The Dynamo, and High Resolution Ring Analysis

1
Meridional Flows, The Dynamo, and High Resolution
Ring Analysis
Deborah Haber, Brad Hindman, Juri Toomre
JILA, University of Colorado
2
Dense-Pack flow field
SUBSURFACE FLOWS FOR TWO SUCCESSIVE DAYS
Magnetic Field Patterns Underlayed (Red-Green)
3
Synoptic Mapping of SSW over Full Rotation
CR 1947
7 Mm DEPTH
Global Patterns of SOLAR SUBSURFACE WEATHER
7-day Averages of Ring-Diagram Inversions
4
Meridional Flows Change as Cycle Progresses
1999
10 Mm
CR 1949
1997
CR 1923
5
Meridional Flow Changes With Depth and Spatial
Position
1 Mm
16 Mm
6
Evolving Mean Meridional Flows
MULTI- ROTATION AVERAGES
2000
2006
2004
1998
1996
2002
VARYING MERIDIONAL CELLS
7
Meridional Flow as Function of Depth and
Latitude
2005
2004
2003
Depth
2002
2001
2000
1999
1998
-60
0
20
40
60
-20
-40
Latitude
8
Full Field Flows H alpha
9
Flows Parallel and Perpendicularto Filament
Neutral Line
10
Summary

• Local Helioseismology has enabled the study of
  meridional flows as a function of depth and
  horizontal position in the upper convection zone.
  
• Meridional flows are not necessarily symmetric
  about the solar equator and change over the
  course of a solar cycle.
• The Solar Dynamics Observatory should enable
  continuous study of these flows.

11

12
(No Transcript)
13
Local Helioseismology Ring-Diagram Analysis

• Analyze acoustic wave fields over mosaic of
  tracked localized regions (each 15 square)
• Measure anisotropic frequency splittings of local
  f and p modes in power spectra
• Invert splittings to deduce flows with depth

INVERSION KERNELS
14
Varying Pattern of Meridional Circulation Cells
NORTH DOUBLE CELL
2001
POLEWARD FLOW NEAR SURFACE
2000
SOUTH SINGLE CELL
REVERSED FLOW AT DEPTH
1999
1998
1997
MULTI- ROTATION AVERAGES
1996
NORTH
SOUTH
15
SSW in Apr 2002
16
Synoptic Mapping of SSW in Apr 2002
10.2 Mm Total
CR 1988
17
SSW Different in Northern Hemisphere
2001
10.2 Mm
CR 1975
1999
CR 1949
18
Synoptic Maps of Two Successive Rotations
1997
7 Mm
CR 1923
CR 1922